The LED provides many advantages over the conventional tungsten light bulb, such as longer life span, power efficiency, durability, reliability, smaller size, and shorter reaction time, and so on. The LED has been widely used in decorative light string, especially with the recent choices of color varieties. However, conventional LED light strings are seldom compatible with the other types of light strings in terms of the voltage, current and the electrical connections. To improve the usability of the LED light string, it is imperative to develop LED light strings that can be used in conjunctions with conventional tungsten light-bulb light strings.
The conventional light strings made with larger tungsten light bulbs are brighter and popular among many consumers. Each tungsten light bulb is with a screw head to screw on the sockets in the light string. The advantage is that each light bulb can be replaced when necessary. The present invention is designed to be compatible with the light bulb with a crew head. In other words, the light string of the present invention can be used to replace the tungsten light bulb with screw head to provide the conventional light strings more varieties of decorative choices.